3. the AC variable frequency speed-regulating motor vehicles can park up and running again in the uphill road, down the ramp you can set any speed, avoid speed. Variable-frequency adjustable-speed motor vehicles can run on 60 ‰ ramps, resistance speed DC motor vehicles to operate only on ramp smaller than 11 per thousand.

4. DC resistance adjusting speed electric locomotive, especially in the frequent start (plus, dump the resistance shift), line power resistor heat consumed away, use DTC control of AC variable frequency speed-governing motor vehicle does not have this problem.